Apparatus and method for securing diamond segment to rotating tool

ABSTRACT

An apparatus for securing one or more diamond segments to a core bit of a diamond core drill includes a coupling ring to which one or more diamond segments are secured. An opposite end of the coupling ring is welded to a core bit. The coupling ring may be steel and may include a tapered portion or groove adjacent to an end of the core bit. An outer diameter formed by the diamond segments may be greater than an outer diameter of the core bit to reduce wear and an inner diameter formed by the diamond segments may be smaller than an inner diameter of the core bit to prevent a core of workpiece material from lodging in the core bit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to diamond-tipped rotating tools used for drilling, cutting and grinding concrete, natural stone and other hard materials. In particular, the invention relates to a device and method for securing diamond segments to a rotatable body of a tool such as a drill core bit or a circular saw core.

2. The Prior Art

Diamond-tipped tools are used for drilling, cutting and grinding concrete, cement, marble, granite, brick, stone, asphalt and other hard materials. Depending on the particular application, a liquid coolant may be supplied to a surface of a rotating diamond-tipped tool (known as wet cutting) or alternatively, a diamond-tipped tool may be used without liquid coolant (known as dry cutting).

Diamond-tipped tools typically comprise one or more diamond segments which are secured to a periphery of a rotatable body or core such as a core bit or saw blade core. The rotatable body is detachably secured to a machine tool, such as a drill or circular saw. Rotatable bodies may range from fractions of an inch to several feet in diameter.

Diamond segments are formed from particles of industrial diamonds and specially blended metal powders which serve as a bonding matrix. The metal powders used to form diamond segments include steel, iron, copper, nickel, cobalt, titanium, bronze and other metals or alloys which are selected as appropriate for a particular application. The diamond particles and metal powder are heated and shaped to form a diamond segment. A sintering process may be used, for example, to form diamond segments. In a finished diamond segment, abrasive diamond particles are distributed throughout the matrix and as the segment wears down during use, fresh diamond particle surfaces are exposed.

The diamond segments are individually secured to a periphery of a rotatable body by, for example laser welding, brazing or soldering. In some applications, the diamond segments may be directly sintered to a rotatable body. The diamond segments may be manufactured with a substantially diamond-free region adjacent to the rotating body which facilitates the attachment of the segment to the body. For example, diamond segments may include an approximately 1/16 inch thick steel strip at a bottom portion of the segment which will be secured to a rotating body.

A rotatable body for a diamond-tipped drilling tool may include a core bit comprising an elongated, hollow steel tube. One end of the core bit is detachably secured to a hand-held or free standing drill. For example, a core bit may have a threaded opening at one end which is secured to a threaded rod portion of a drill. The other end of the core bit has one or more diamond segments secured around its circumference. The diamond segments may be secured by, for example, laser welding. The diamond segments may be arranged on the circumference of an end of the core bit with a fixed spacing between adjacent diamond segments.

An outer diameter formed by the diamond segments secured to the core bit defines a diameter of a hole drilled by the diamond core bit. An inner diameter formed by the diamond segments secured to the core bit defines a diameter of a cylindrical core of the material being drilled. The cylindrical core is enclosed within the core bit as the diamond tipped drill is advanced through the material being drilled,

A rotatable body for a diamond-tipped cutting or grinding tool may include a blade core comprising a relatively flat circular steel disc. A bore though the center of the blade core is provided for detachably securing the blade core to a saw. One or more diamond segments are secured around the circumference of the blade core.

As a diamond-tipped tool is used, the diamond segments secured to the rotatable body wear until the tool is no longer suitable for use. Additionally, individual diamond segments may break or dislodge from the rotatable body.

The methods discussed above for securing diamond segments to a rotating body require considerable skill, specialized equipment and/or substantial time and cost, making them unsuitable for repairing or replacing worn or damaged diamond segments, especially at a job site. Accordingly, when one or more diamond segments become worn or damaged, a user may discard the entire rotatable body, whether it be a core bit or a blade core. The rotatable body may comprise a substantial metal component which must then be replaced at significant cost.

With respect to core bits, the outer diameter formed by the diamond segments is often quite close in dimension to the outer diameter of the metal tube forming the core bit to which the segments are secured. As a result, during use the core bit comes into vibrational contact with the hard workpiece material at the walls of the hole being drilled. This results in damage and wear to the core bit and shortens its effective life. Additionally, the inner diameter formed by the diamond segments is often quite close in dimension to the inner diameter of the metal tube forming the core bit to which the segments are secured. As a result, the cylindrical core of material removed from the workpiece can become lodged in the core bit and may be difficult or impossible to remove. Users may damage or destroy the core bit while attempting to dislodge the core.

Accordingly, there exists a need for a simple and inexpensive apparatus and method for replacing and securing diamond segments to a rotatable body such as a drill core bit or a circular saw blade so that the rotatable body may be reused. Additionally there exists a need to reduce wear on a diamond core bit caused by contact with a wall of a hole being drilled. Furthermore, there exists a need to eliminate the problem of cylindrical cores becoming lodged within a diamond core bit.

SUMMARY OF THE INVENTION

This invention relates to a device and method for securing diamond segments to a rotatable body of a tool such as a drill core bit or a circular saw core. In an embodiment according to the invention a coupling ring is concentric with a with a core bit of a diamond core drill. One or more diamond segments are secured around the circumference of one side of a coupling ring. A second side of the coupling ring is secured to an end of the core bit, for example by welding the coupling ring to the core bit. A second side of the coupling ring may have a tapered profile which allows the coupling ring to be easily aligned with the core bit and provides a suitable surface for welding or otherwise joining the coupling ring and core bit. A second side of the coupling ring may include a groove on its face which corresponds to a wall thickness of a core bit. Ths groove may facilitate aligning the coupling ring with the core bit prior to joining the coupling ring to the core bit. The coupling ring may comprise a steel ring.

An outer diameter formed by the one or more diamond segments secured around a coupling ring may be greater than an outer diameter of a core bit onto which the coupling ring is welded. An inner diameter formed by the one or more diamond segments secured around a coupling ring may be smaller than an inner diameter of a core bit onto which the coupling ring is welded.

In a method according to an embodiment of the invention one or more diamond segments are secured to one side of a coupling ring and a second side of the coupling ring is welded or otherwise joined to a core bit of a diamond core drill. A user of a core bit having diamond segments which have become worn or damaged may remove an end of the core bit including the worn or damaged diamond segments, for example by cutting, and then join a coupling ring to which one or more diamond segments have been secured to the cut end of the core bit.

According to another embodiment of the invention, slots or grooves are provided in a side of a diamond segment to be secured to a core bit or circular saw core. The slots or grooves allow a user to easily align individual diamond segments to a core bit or circular saw core for securing the segments to the core bit or saw core.

One advantage of an apparatus according to the invention is that a coupling with one or more diamond segments secured to it can be easily welded to an end of a core bit at a job site or in the field. This can eliminate or reduce the the need to discard the entire core bit when one or more diamond segments become broken or worn. An end of a core bit having broken or worn diamond segments is simply cut off and a coupling with diamond segments is welded onto the end of the core bit. This provides a savings in time and cost.

Another advantage of an apparatus according to an embodiment of the invention is that it results in less vibration and wear on the core bit because an outer diameter formed by the diamond segments is greater than an outer diameter of the core bit. This provides for greater clearance between the core bit and the material on the sides of the hole being drilled.

Another advantage of an apparatus according to an embodiment of the invention is that it is easier to remove a cylindrical core of material being drilled from the core bit. Since an inner diameter formed by the diamond segments is smaller than an inner diameter of the drill core, the cylindrical core of material does not lodge in the drill core.

Another advantage of an embodiment according to the invention is that slots or grooves provided in a diamond segment allow users to easily align the diamond segment with a core bit, coupling ring or circular saw core to which the diamond segment is to be attached.

BRIEF DESCRIPTION OF THE DRAWINGS

Other benefits and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

In the drawings, wherein similar reference characters denote similar elements throughout the several views:

FIG. 1 shows two types of drilling devices which can be used with diamond core drills in conjunction with an apparatus according to an embodiment of the invention;

FIG. 2 shows a prior art core bit with diamond segments secured thereto;

FIG. 3 shows an apparatus for securing diamond segments to a core bit of a diamond core drill according to an embodiment of the invention;

FIG. 4 shows an apparatus for securing diamond segments to a core bit of a diamond core drill according to another embodiment of the invention;

FIG. 5 shows a grooved diamond segment for securing to a circular saw core or core bit; and

FIG. 6 shows an apparatus for securing diamond segments to a core bit of a diamond core drill according to another embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now in detail to the drawings, FIG. 1 shows examples of various types of drilling devices which can be used with diamond core drills. The drilling devices may be handheld or mounted on a stand or support. The drilling devices may include a means for supplying fluid to a surface of a workpiece for cooling and carrying away debris.

FIG. 2 shows a prior art diamond core bit 2. Diamond core bit 2 may comprise a hollow elongated steel tube 21. One end 22 of core bit 2 may have a threaded opening 23 for detachably securing the core bit 2 to a drilling device. Core bit end 22 may also include one or more pairs of parallel surfaces (not shown) for removing core bit 2 from a drilling device with a wrench or similar tool.

Another end 24 of core bit 2 has one or more diamond segments 25 secured around its circumference. Diamond segments 25 may be arranged on a circumference of end 24 of core bit 2 with a fixed spacing between adjacent diamond segments and may be secured by, for example, laser welding.

FIG. 3 shows an embodiment of an apparatus for securing diamond segments to a core bit of a diamond core drill. One or more diamond segments 31 are secured around a circumference of a face of a hollow coupling ring 32. Coupling ring 32 is concentric with an end 24 of a core bit. Coupling ring 32 may comprise a hollow steel ring. As shown in FIG. 3, coupling ring 32 with one or more diamond segments 21 is secured to an end 24 of a core bit, for example by welding.

Coupling ring 32 may include a tapered portion 33 and a reduced diameter portion or lip 35 at an end or face adjacent to end 24 of core bit. Tapered portion 33 and reduced diameter portion 35 allow a user to easily align coupling ring 32 with the core bit to which it is to be attached. Tapered portion 33 may also provide a suitable surface for welding or otherwise joining coupling ring 32 to end 24 of core bit.

Tapered portion 33 may have an angle of approximately 45 degrees with respect to the longitudinal axis of the core bit. Reduced diameter portion 35 may extend substantially parallel to the longitudinal axis of the core bit.

Coupling ring 32 may be secured to a core bit by a weld 34 which extends substantially around an entire circumference of coupling ring 32 and a core bit. Alternatively, coupling ring 32 may be joined to a core bit with an adhesive or a mechanical fastener.

When the diamond segments of a diamond core drill become worn or damaged, a user may remove an end of the core bit including the worn or damaged diamond segments. For example, a user may remove a portion from the end of the core bit with a hand or powered saw. The user may then replace the worn or damaged section which has been removed with a coupling ring to which at least one diamond segment has been secured. The coupling ring is welded or otherwise joined or fastened to a cut end of the core bit. In this way, a user can quickly and easily repair or replace damaged core bits in the field and the need to discard a core bit when diamond segments become worn or damaged is eliminated. Furthermore, a single core bit may be used multiple times by removing an end portion and securing a new coupling ring with its attached diamond segments each time the segments become unusable. A depth of a coupling ring is such that it extends only a short distance into a core bit and does not interfere with the cutting off of a damaged or worn core bit end.

As shown in FIG. 3, one or more diamond segments 31 may be arranged spaced apart on coupling ring 32. Additionally, one or more diamond segments 31 may form an outer diameter which is greater than an outer diameter of a core bit to which coupling ring 32 with diamond segments 31 is attached. Furthermore, one or more diamond segments 31 may form an inner diameter which is smaller than an inner diameter of a core bit to which coupling ring 32 with diamond segments 31 is attached. This configuration reduces wear on a core bit to which an apparatus according to the invention is welded and facilitates removal of a core of workpiece material from the drill core.

FIG. 4 shows another embodiment of an apparatus for securing diamond segments to a core bit of a diamond core drill. In the embodiment shown in FIG. 4, a groove or slot 41 is disposed in a face of a side of coupling ring 32 facing a core bit. A width of groove 41 may be approximately equal or slightly greater than a wall thickness of a core bit to which coupling ring 32 is to be attached. An end of a core bit fits into groove 41 and coupling ring 32 with diamond segments 31 may be secured to the core bit by, for example, welding.

FIG. 5 shows another embodiment of the invention wherein individual diamond segments 51 are provided with a slot or groove 52 on a face of diamond segment 51 which is to be secured to a circular saw core 53 or a drill core end 24. A width and curvature of slot or groove 52 may correspond to a width and curvature of a circular saw core 53 or drill core end 24 to which diamond segments 51 are to be secured. Groove or slot 52 may be formed by grinding an existing diamond segment or diamond segments may be formed with a groove or slot. Groove or slot 52 permits a user to align diamond segments 51 to a circular saw core 53 or core bit end 24 to which they are to be attached. Diamond segments 51 may be secured to a circular saw core 53 or drill core end 24 by, for example, welding or brazing.

FIG. 6 shows another embodiment of an apparatus for securing diamond segments to a core bit of a diamond core drill. In the embodiment shown in FIG. 6, coupling ring 32 includes a tapered portion or chamfer 33 at an end or face adjacent to end 24 of core bit. Tapered portion 33 may have an angle of approximately 30-35 degrees with respect to the longitudinal axis of the core bit. Tapered portion or chamfer 33 allows a user to easily align coupling ring 32 with the core bit to which it is to be attached. Tapered portion 33 may also provide a suitable surface for welding or otherwise joining coupling ring 32 to end 24 of core bit.

The embodiment illustrated in FIG. 6 may be particularly useful for securing diamond segments to an end of a core bit which has become out-of-round due to wear or impact. An end 24 of a core bit may become egg-shaped or oval-shaped or otherwise out-of-round as a result of wear or impact. Coupling ring 32 including diamond segments 31 and tapered portion or chamfer 33 having an angle of approximately 30-35 degrees may be placed over an out-of-round end of a core bit. A hammer, mallet or similar tool may be used to urge coupling ring 32 into fit with the core bit.

Accordingly, while several embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention. 

1. An apparatus for securing diamond segments to a core bit of a diamond core drill, the apparatus comprising: (a) a coupling ring concentric with the core bit and having a first side and a second side; (b) at least one diamond segment secured on a circumference of said first side of said coupling ring; and (c) a fastener joining said second side of said coupling ring to an end of the core bit.
 2. The apparatus according to claim 1, wherein said fastener joining said second side of said coupling ring to said end of the core bit further comprises a weld.
 3. The apparatus according to claim 1, wherein said end of the core bit comprises an end which has been cut to remove a damaged or worn diamond segment.
 4. The apparatus according to claim 1, wherein said second side of said coupling ring further comprises a tapered profile.
 5. The apparatus according to claim 4, wherein said tapered profile allows said coupling ring to be aligned with said end of the core bit.
 6. The apparatus according to claim 1, further comprising a groove disposed on a face of said second side of said coupling ring.
 7. The apparatus according to claim 6, wherein a width of said groove is approximately equal to or greater than a wall thickness of the core bit.
 8. The apparatus according to claim 1 wherein an outer diameter formed by said diamond segments secured around a circumference of said first side of said coupling ring is greater than an outer diameter of the core bit.
 9. The apparatus according to claim 1 wherein an inner diameter formed by said diamond segments secured around a circumference of said first side of said coupling ring is smaller than an inner diameter of the core bit.
 10. The apparatus according to claim 1 wherein said coupling ring comprises a steel ring.
 11. A method for securing diamond segments to a core bit of a diamond core drill, the method comprising the steps of: (a) securing at least one diamond segment to a circumference of a first side of a coupling ring; and (b) joining a second side of said coupling ring to an end of a core bit of a diamond core drill.
 12. The method according to claim 11, further comprising the step of removing an end of the core bit which includes a damaged or worn diamond segment prior to joining said coupling ring to the core bit.
 13. The method according to claim 11, wherein said step of joining said second side of said coupling ring to said end of the core bit further comprises welding said second side of said coupling ring to said end of the core bit.
 14. A diamond segment for securing to a core bit or circular saw core comprising a-plurality of diamond particles disposed in a matrix and having a groove disposed on a face of the diamond segment adjacent to the core bit or circular saw core.
 15. The diamond segment according to claim 14 wherein said groove has a width which is approximately equal to a width of the circular saw core or to wall thickness of the core bit. 